A suspected suicide bomber has attacked a foreign military convoy on the eastern outskirts of the Afghan capital, killing at least three foreign soldiers.

The Taliban claimed responsibility for the attack in Kabul which comes as president Hamid Karzai deliberates over an agreement allowing United States forces to stay in the country beyond 2014.

The NATO-led International Security Assistance Force (ISAF) released a statement confirming the death of three service members. It gave no more details.

A Taliban spokesman claimed responsibility in a message on his Twitter account.

"A number of foreign forces were killed and wounded and many vehicles were also destroyed," the militant spokesman said.

Many Afghans, including a gathering of 3,000 tribal leaders and other prominent people, have urged Mr Karzai to sign the US pact quickly as they worry about security after 2014 when most foreign forces are leaving.

Mr Karzai says he does not want to sign until after a presidential election scheduled for April next year and unless the US fulfils a number of his demands.